iPhone OS 4.0 Only For 3G and 3GS?

According to a source, the new iPhone OS 4.0, which is rumored to be shown at the upcoming Apple event; will include multitasking, which has been wanted for a long time but many iPhone users but only those who jailbreak the device can use this feature. The source also says there will be a new UI, “to make navigating through the OS easier and more efficient” and also OS-wise mutli-touch gestures. However I see it unlikely that Apple will majorly change the UI of the OS as they like to keep things familiar.

The source also says how they will also be “some brand new syncing ability for the contacts and calendar applications” but that the new OS will only be available for the iPhone 3G and 3GS, this makes sense for the multitasking as the iPhone 2G doesn’t have enough RAM to be able to multitask properly.